Compare

Eunotia orthohedra belongs to the E. exigua complex, based on size and general features. Eunotia orthohedra is distinct from E. exigua, E. tenella and E. cataractarum, based on the distinct, straight dorsal margin of E. orthohedra.

LM scalebar = 10 µm
Eunotia orthohedra LM3 Eunotia orthohedra LM5 Eunotia orthohedra LM4 Eunotia orthohedra LM1 Eunotia orthohedra LM2
Length Range
12-19 µm
Width Range
2.7-3.8 µm
Striae in 10 µm
16-20 in the valve center, 20-22 at the ends

Eunotia cataractarum

Furey, Lowe and Johansen 2011

Eunotia cataractarum LM5 Eunotia cataractarum LM6 Eunotia cataractarum LM1 Eunotia cataractarum LM4 Eunotia cataractarum LM3 Eunotia cataractarum LM2 Eunotia cataractarum LM7
Length Range
11-21 µm
Width Range
3.1-3.9 µm
Striae in 10 µm
15-20 in the center valve, 16-19 at the ends, puncta 44-50

Also compare to

Eunotia exigua

(Bréb.) Rabenh.

Eunotia tenella

(Grunow) Hust.